Firestore query documents with only collections inside

Question

I have a firestore collection which has some documents inside it. The documents contains only collections not any fields. So when I try to get all documents inside the root coll

Answer 1

Adapted from Get Data with Cloud Firestore

db.collection("transactions").doc("2018-01-02").collection("education-1").get()
    .then(function(querySnapshot) {
        querySnapshot.forEach(function(doc) {
            // doc.data() is never undefined for query doc snapshots
            console.log(doc.id, " => ", doc.data());
        });
    })
    .catch(function(error) {
        console.log("Error getting documents: ", error);
    });

Answer 2

let date = '2017-12-20' //date to be set in doc

db.collection("transactions").doc(date).set({
  //set an empty object for each doc in transaction before your method 
  //of setting data 
  //This will create a field for each doc in transaction
})
.then(()=>{
  //your method of setting data here.
})
//Your query method here.
//Now you will be able to query the docs in collection - transaction.